Spondylus requienianus Matheron, 1842
MATHERON, P. 1842. Catalogue méthodique et descriptif des corps organisés fossiles du Département des Bouches-du-Rhône et lieux circonvoisins. 269 p., pls. 1-41. Carnaud Fils, Imprimeur. Marseille, 1842. [p. 189, pl. 32, fig. 3]
1842 Spondylus requienianus Matheron, 1842
P. Matheron, 1842, plate 32.
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«S. testâ ovatâ, subobliquâ, longitudinaliter confertim sulcatâ, concentricè striatâ; valvâ inferiore convexâ, ad natem subfoliaceâ, nate truncatâ, areâ cardinali latâ; valvâ superiore convexo-planâ, sulcis profondioribus costellis rudis, elevatis separatis, umbone brevi, sessili; margine valvarum subcrenato.
Cette espèce a quelques rapports avec le podopsis truncata de LAMARCK.
Longueur de la grande valve 85 millim.; longueur de la valve superieure 58 millim.; largeur 58 millim.; hauteur 66 millim. Craie chlorit. 24. c. Uchaux et Mornas.» PHILIPPE MATHERON, 1842
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«Description: Small to medium-sized Spondylus species with strongly convex, rounded to elongate, right valve andsuborbicular left valve. The shape of the right valve depends on the morphology of the substrate, the umbo is prominent and often recurved with high triangular cardinal area (PI. XIII, figs 12a-15b). The flat to fairly convex left valve has triangular and narrow auricles, covered with riblets which are almost perpendicular to the umbonal folds.
Ornamentation consists of numerous (40-75) ribs, which are relatively wide and divided by narrow interspaces when the shell is complete, but narrow with wide interspaces when the external layer has been peeled off. Ribs are straight on the median part of the valve, but diverge towards the anterior and posterior valve margins. The rib number increases by bifurcation. Neither spines, nor spine-bases have been observed. In Text-fig. 11 the L/H ratios for right and left valves from Pinei are illustrated. The small studied sample shows that the values of the ratios of the irregular attached right valves are scattered and those of the free left valves are distributed more regularly.
Discussion: The specimens from the Lago di S. Croce area are somewhat smaller than those described from Provence or known from the Gosau in Austria. Smaller specimens are also known from the Gosau but they were generally given a different name (such as Sp. coquandianus d'Orbigny, 1847, originally described from Turonian-Senonian beds in SE France).
By its lack of spines and by its subequal ribs, Sp. requienianus differs from Sp. fimbriatus Goldfuss, 1835 (= Sp. dutempleanus d'Orbigny, 1847; see Dhondt and Dieni, 1990), from the Cenomanian to Maastrichtian of Europe, and from Sp. hippuritarum d'Orbigny, 1847, from the Turonian-Coniacian of southern France; it has only half as many ribs, a larger attachment area, a more convex and less regular right valve than Sp. latus (J. Sowerby, 1815), from the Cenomanian to Campanian chalks of Europe. For the differentiation from Sp. arcuatus (Catullo, 1834), see above. Lima vallismontanae Marinelli, 1902 from "Senonian" beds near Tarcento (Friuli) is not a limid, but a spondylid, as can be seen from the original description and figures. It is almost certainly synonymous with Spondylus requienianus, but we have not been able to definitely prove this synonymy because its types are at present missing from the collections of the Museo di Geologia e Paleontologia, University of Florence. Distribution: All known occurrences of Spondylus requienianus (Uchaux, SE France; Gosau area, Austria; eastern Venetian and Carnic Prealps, Gorizia and Trieste Karst, NE Italy; Istria, Croatia) vary in age from Turonian to Early Campanian and are from Tethyan rudist formations.»
DHONDT, A. V. & I. DIENI. 1993. Non-rudistid bivalves from Late Cretaceous rudist limestones of NE Italy (Col di Schiosi and Lago di S. Croce areas). Memorie di Scienze Geologiche, 43: 165-241, pls. 1-20, text-figs. 1-18. [p. 206]
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SpondyIus requienianus Matheron, 1843; A. Dhondt & I. Dieni, 1993, Non-rudistid bivalves from Late Cretaceous rudist limestones of NE Italy (Col di Schiosi and Lago di S. Croce areas), plate 13, figures 4-15b.
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«Type-material:
MATHERON specimen: Probably in the Rénaux Coll., University of Montpellier, France. ZITTEL specimen: NHMW. Locus typicus, stratum typicum: Uchaux, Vaucluse (France), Upper Turonian. Description and discussion: Material from the Hochmoos Fm. at Bibereck: Two right attached valves, inside exposed (one from the SKOUMALCOII., Vienna). Description: The attached valves seen from the inside show numerous, narrow radial ribs, not always straight and not all of the same width. The valves are much wider than height. Discussion: As stated above it is plausible that the Hochmoos Fm. specimens of Spondylus requienianus are large valves of Sp. coquandianus. Ontogenetic series of Cretaceous attached spondylids are not generally available. On the valves from Bibereck only the inside is exposed, so it is not possible to judge the ontogenetic shape changes, which would prove the hypothesis on conspecificity of the two species of Spondylus identified from the Hochmoos Fm. Occurrence and distribution: Spondylus requienianus has been recorded from Santonian Gosau deposits and from Coniacian S. E. French deposits.» DHONDT, A. V. 1987. Bivalves from the Hochmoos Formation (Gosau-Group, Oberösterreich, Austria). Annalen der Naturhistorischen Museums in Wien, 88: 41-101, pls. 1-6. [p. 71]
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Spondylus requienianus Matheron, 1843; A. V. Dhondt, 1987, Bivalves from the Hochmoos Formation (Gosau-Group, Oberösterreich, Austria), plate 4, figure 9.
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